Ice release coatings

ABSTRACT

A compound is provided, having the formula (I), wherein R S  is a soft block polymer; wherein each T is independently a urethane or urea linkage; see formulae (A) and (B); wherein each R D  is independently —CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , or —CH 2 CH 2 CH 2 CH 3 ; wherein each R′ D  is independently —CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 CH 2 CH 2 CH 3 , or —OR D ; and wherein each p is independently 1, 2, or 3. Compositions containing the compound, and methods of making and using the compound are provided.

REFERENCE TO AN EARLIER APPLICATION

This application is a continuation application of U.S. application Ser.No. 15/025,888, filed Sep. 30, 2014, as a 371 National Stage Entry ofPCT International Application No. PCT/US14/58499, now U.S. Pat. No.10,221,333, issued Mar. 5, 2019, which claims priority to U.S.Provisional Application No. 61/884,986, filed Sep. 30, 2013, the entirecontents of each of which are hereby incorporated by reference.

GOVERNMENT LICENSE RIGHTS

This invention was made with government support under grant number(s)DMR0802452 and DMR1206259 awarded by the National Science Foundation(NSF) and N00014-09-1-0780 awarded by NAVY/ONR. The government hascertain rights in the invention.

FIELD OF THE APPLICATION

The present application relates to polymer coatings and coatingcompositions, methods of making, and their use.

BACKGROUND

Ice accumulation is a serious problem for many industries includingaerospace, marine, wind energy, power utilities, refrigeration, andcommercial fishing.

Telecommunications towers are affected in cold environments when icingon exposed structures causes damage. Icing leads to material loss,reduced performance, and interference with normal operations. Icingoften leads to injuries and sometimes to deadly accidents.

Because of the broad range of effected sectors, there is no universalsolution to ice accumulation. Use of the term “ice-phobic”, whichsuggests some surfaces prevent ice formation, is incorrect as no coatingor surface prevents ice formation under all icing conditions. Dependingon the application, the desired outcome is usually the prevention of iceaccumulation through easy removal at an early stage of accretion by“natural” forces including wind, vibration, or centrifugal force. Theextent of accumulation that can be tolerated varies greatly as does thedegree to which ice can be removed from a surface by “natural means”.For throwing office by centrifugal force, a coating technology must takeinto account that the surface of a wind turbine blade close to the rotormoves much more slowly than the tip of the blade. Power lines are fixed,but may undergo substantial flexing due to wind and vibration.

Perhaps the most demanding applications requirements are those posed bythe aerospace industry. These applications have strict requirements formaximum tolerable mass and for uncompromised reliability. It is wellknown that airfoil icing disrupts airflow, reduces lift, and jeopardizescontrol. Currently, the aviation industry broadly employs activeanti-icing (e.g., heating) to mitigate icing related problems.

Ice accumulation on airplane wings must be removed before takeoff,typically with ethylene or propylene glycol-based fluids or foams. EPAestimated more than 25 million gallons of de-icing agents are annuallyapplied at commercial US airports. De-icing agents are normally notrecycled and are discharged directly into waste water systems. Suchdischarge has caused increased biological oxygen demand and totalorganic content in groundwater. For the aviation industry, de-icingagents are the method of choice despite the environmental concerns. Asmore environmentally benign de-icing methods are developed andenvironmental regulations become stricter, alternatives such as highlyefficient ice release coatings will be sought.

Power transmission and telecommunications often encounter problems fromicing. In these instances, billion dollar losses can be suffered inmajor winter storms. In December, 2008, an ice-storm crippled theeastern New England states. The storm impacted an area of 3,250 squaremiles of the National Grid power company's service area inMassachusetts, N.H. and Rhode Island. National Grid had to repair orreplace more than 416,000 feet of distribution wire.

The industrial freezer industry has icing problems that are notgenerally known or appreciated. In commercial freezer facilities,processed foods are transferred into “blast freezer” rooms where liquiddripping from the food forms ice on the floors. Another problem forindustrial freezers is ice development around the entrance doors tofreezer sections. For this application, manufacturers of refrigerationunits seek ice-release coatings that bond well to substrates such ashigh impact polystyrene. Other problems for which ice-release coatingsoffer promise include amelioration of blockage of drains and “icing-up”of air conditioners.

From the above summary, market needs for products from which ice can beremoved easily vary widely in terms of technical requirements andchallenges.

Currently used active methods for de-icing include de-icing fluids foraircraft discussed above and resistive heating where ample power isavailable such as wind turbines, automobile windshields, andrefrigeration units. Resistive heating is costly to implement andreduces net power generated from wind farms. Passive de-icing methodssuch as icephobic and ice-release coatings are based on silicones orfluoropolymers. Silicones are known for their weak mechanical propertiesand high cost. Fluorocarbon polymers, if used in the neat form, are evenmore expensive than silicone materials.

It is logical to think that ice cannot form if water does not wet thesurface. Therefore, superhydrophobic surfaces have been investigated toachieve icephobic surfaces. In most cases, such surfaces require carefulmicrostructural fabrication or electrospinning to generate specificcomplex microstructures for samples that have dimensions of a few squarecentimeters. Such complex processes are not applicable for large surfaceareas, at least at present.

A common but mistakenly held notion is that polytetrafluoroethylene(PTFE) or “Teflon” should be good for ice release. Teflon and similarsemicrystalline fluoropolymers are processable at high temperatures togenerate “non-stick” surfaces for cookware and the like. However, suchhigh temperature processes are not applicable for large area coatingtechnologies. Secondly, polymers made of long fluorocarbon chains (>C6)are degradable to perfluorooctanoic acid (PFOA) that persistsindefinitely in the environment. PFOA is bioaccumulative and is a provencarcinogen. Again, current technologies are inadequate.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 presents GPC results for homemade TPU, commercial TPU andpurified commercial TPUs.

FIG. 2 presents a representative force-distance curve showing peakremoval force P_(s) for PTMO-40 50 μm thick hybrid coating (ER-coat-1).

FIG. 3 presents a representative force-distance curve showing peakremoval force Ps for PTMO-40 with 1 wt % PDMS 50 μm thick coating(i-Coat-2).

FIG. 4 presents peak removal forces for various coatings.

FIG. 5 presents contributions of nanosurface, mesosurface and bulk toadhesion in shear. Kendall's theory, adapted for ice removal: PeakRemoval Force in shear is designated P_(s) correlates coatingparameters: work of adhesion (wa), modulus (K), and thickness (t) withpeak removal force P_(s). Ps∝A(2w_(a)K/t)^(1/2) (Eq. 1) (Kendall, K. J.Physics D Applied Physics 1971, 4, 1186-1195).

FIG. 6 shows apparatus for ice adhesion measurement: A, TA InstrumentsRSA III dynamic mechanical analyzer with temperature-controlled chamber;B, ice cylinder on transparent coating in sample holder.

FIG. 7 shows a representative force-distance curve showing peak removalforce Ps. This run is one of several acquired on 50 μm ER-coat-2 toexplore reproducibility (see FIG. 8).

FIG. 8 shows peak removal force for three independently prepared andprocessed ER-coat-2 coatings with 1 wt % PDMS. Several ice releasetrials were used for each run.

FIG. 9 shows peak removal force dependence on the surface modifierweight percent for 50, 100 and 150 μm. Circled shows ER-coat-2, 1 wt %PDMS, 50 μm.

FIG. 10 shows peak removal force as a function of TPU content (hybridcontent) for ER-coat-1 without surface modifiers. *Cohesive failure wasobserved for 100% TPU coatings.

FIG. 11 shows peak removal force dependence on coating thickness for thebase hybrid system using PTMO hybrid and TPU system without surfacemodifier.

FIG. 12 presents an illustration of ice adhesion test using the AdverseEnvironment Rotor Test Stand (AERTS) at the Vertical Lift ResearchCenter of Excellence (VLRCOE), in Aerospace Engineering at Penn State.

FIG. 13 shows results of ice adhesion test using the Adverse EnvironmentRotor Test Stand (AERTS) in the Vertical Lift Research Center ofExcellence (VLRCOE) of Penn State.

FIG. 14 shows peak removal force of PDMS modified coatings at −10° C.(left bars) and −20° C. (right bars) at three PDMS loading levels (1%,2% and 3%) and three thicknesses (50, 100 and 150 μm).

BRIEF SUMMARY OF THE SEVERAL EMBODIMENTS

One embodiment provides a compound having the formula (I):

wherein R_(S) is a soft block polymer,

wherein each T is independently a urethane or urea linkage;

wherein each R_(D) is independently —CH₃, —CH₂CH₃, —CH₂CH₂CH₃, or—CH₂CH₂CH₂CH₃;

wherein each R′_(D) is independently —CH₃, —CH₂CH₃, —CH₂CH₂CH₃,—CH₂CH₂CH₂CH₃, or —OR_(D); and

wherein each p is independently 1, 2, or 3.

In one embodiment, the soft block polymer R_(S) is not a polyoxetane.

In one embodiment, the soft block polymer R_(S) is a polyether,polydiene, polyolefin, polysiloxane, polyester, or combination thereof.In one embodiment, soft block polymer is derived from a diol, diamineendcapped polyether, polydiene, polyolefin, polysiloxane, polyester, orcombination thereof.

In one embodiment, the soft block polymer R_(S) is a linear homopolymeror copolymer. In one embodiment, the soft block polymer R_(S) is ahomopolymer.

In one embodiment, the soft block polymer R_(S) has a molecular weight,M_(w), of 200-10,000 Da. This range includes all values and subrangestherebetween, including 200, 225, 250, 300, 400, 450, 500, 600, 700,800, 900, 1000, 2000, 2500, 5000, 7500, and 10000.

In one embodiment, the T is independently a urethane linkage or urealinkage.

In one embodiment, each R_(D) is independently —CH₃ or —CH₂CH₃.

In one embodiment, each R′_(D) is independently —CH₃, —OCH₃, or—OCH₂CH₃.

In one embodiment, each R_(D) is —CH₂CH₃, and each R′_(D) is —OCH₂CH₃.

In one embodiment, two or more different compounds having formula (I)may be present in a composition, wherein a first soft block polymerR_(S) in one compound having formula (I) has a molecular weight, M_(w),of 200-1,000 Da, and a second soft block polymer R_(S) in a differentcompound having formula (I) has a molecular weight, M_(w), of1,500-3,000 Da. These ranges include all values and subrangestherebetween, including 200, 225, 250, 300, 350, 400, 450, 500, 550,600, 650, 700, 750, 800, 850, 900, 950, and 1000 Da; and 1,500, 1550,1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, 2000, 2100, 2200, 2300,2400, 2500, 2600, 2700, 2800, 2900, and 3000 Da.

In one embodiment, the soft block polymer R_(S) is a polytetramethyleneoxide having a molecular weight, M_(w), of 250 Da.

In one embodiment, the first soft block polymer R_(S) has a molecularweight, M_(w), of 200-500 Da, and a second soft block polymer R_(S) in adifferent compound having formula (I) has a molecular weight, M_(w), of1,500-2,000 Da.

In one embodiment, the first soft block polymer R_(S) is apolytetramethylene oxide having a molecular weight, M_(w), of 250 Da,and a second soft block polymer R_(S) is a polytetramethylene oxidehaving a molecular weight, M_(w), of 2,000 Da.

In the case of a composition wherein more than one soft block R_(S) isused, the weight ratio of first and second R_(S) is not particularlylimited, and may range from >0-<100 wt %: <100->0 wt %. These rangesinclude all values and subranges therebetween, including >0, 1, 2, 3, 4,5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75,80, 85, 90, 95, 99, and <100 wt % as appropriate.

One embodiment provides a method of making the above compound,comprising:

-   -   reacting, in the presence of a catalyst, one or more soft block        polymers R_(S) end-capped with —NH₂, —OH, or combination        thereof,    -   with one or more compounds having the formula:

-   -   to form the compound.

In one embodiment, the end-capped soft block polymer R_(S) has theformula H₂N—R_(S)—NH₂ or HO—R_(S)—OH.

In one embodiment, the catalyst is one or more of condensation curecatalyst, dibutyltin dilaurate, dibutyltin diacetate,diazabicyclo[2.2.2]octane, 1,3-diacetoxy-1,1,3,3-tetrabutyltin oxide,di-n-butylbis(1-thioglycerol)tin, di-n-butyldiacrylate,di-n-butyldi-n-butoxytin, di-n-butyldimethacrylatetin, platinumcatalyst, addition cure catalyst, or combination thereof.

In one embodiment, the “hybrid” composition comprises a reaction productof:

-   -   (A) one or more compounds having formula (I);    -   (B) one or more alkoxysilane, alkoxysiloxane, or combination        thereof as mesosurface builder;    -   (C) optionally, one or more polydialkylsiloxane diol as first        nanosurface modifier,    -   (D) optionally, one or more fluorinated alkoxysilane as second        nanosurface modifier, and    -   (E) optionally, one or more of a catalyst, water, or combination        thereof.

In one embodiment, as used herein, the “hybrid” reaction product is thatwhich is obtained after the reaction proceeds to a completion greaterthan about 30%. This range includes all values and subrangestherebetween, including 30, 40, 50, 60, 70, 80, 90, 95, 99, and 100%.

In one embodiment, the composition comprises a reaction product of:

-   -   (A) one or more compounds having formula (I);    -   (B) one or more alkoxysilane, alkoxysiloxane, or combination        thereof as mesosurface builder;    -   (C) one or more polydialkylsiloxane diol as first nanosurface        modifier; and    -   (E) optionally, one or more of a catalyst, water, or combination        thereof.

In one embodiment, the composition comprises a reaction product of:

-   -   (A) one or more compounds having formula (I);    -   (B) one or more alkoxysilane, alkoxysiloxane, or combination        thereof as mesosurface builder;    -   (C) one or more polydialkylsiloxane diol as first nanosurface        modifier;    -   (D) one or more fluorinated alkoxysilane, fluorinated        polydialkylsiloxane diol, or combination thereof as second        nanosurface modifier, and    -   (E) optionally, one or more of a catalyst, water, or combination        thereof.

In one embodiment, the mesosurface builder (B) is one or more ofpoly(diethoxysiloxane) (PDEOS), poly(dimethoxysiloxane) (PDMOS),1,2-bis(triethoxysilyl)ethane (BTESE), 1,4-bis(triethoxysilyl)benzene1,2-bis(triethoxysilyl)ethylene, bis(triethoxysilyl)methane,1,8-bis(triethoxysilyl)octane, 1,10-bis(trimethoxysilyl)decane,1,6-bis(trimethoxysilyl)-2,5-dimethylhexane,1,2-bis(trimethoxysilyl)ethane, bis(trimethoxysilylethyl)benzene,1,6-bis(trimethoxysilyl)hexane, 1,4-bis(trimethoxysilylmethyl)benzene,1,8-bis(trimethoxysilyl)octane, or combination thereof. In oneembodiment, the

In one embodiment, the first nanosurface modifier (C) ispolydimethylsiloxane diol, polydiethylsiloxane diol, or combinationthereof.

In one embodiment, the first nanosurface modifier (C) has a molecularweight, M_(w), of 200-50,000 Da. This range includes all values andsubranges therebetween, including 200, 225, 250, 300, 400, 450, 500,600, 700, 800, 900, 1000, 2000, 2500, 3000, 3500, 4200, 4500, 5000,5500, 6000, 6500, 7000, 7500, 10000, 15000, 20000, 25000, 26000, 30000,35000, 40000, 45000, 50000, and any combination thereof.

In one embodiment, the first nanosurface modifier (C) ispolydialkylsiloxane diol having a molecular weight, M_(n), of 4200 Da.In one embodiment, the first nanosurface modifier is apolydimethylsiloxane diol.

Optionally, a second nanosurface modifier (D) may be present.Nonlimiting examples of the second nanosurface modifier includepoly[methyl(3,3,3-trifluoropropyl)siloxane] diol,pentafluorophenyltrimethoxysilane,3-(heptafluoroisopropoxy)propyltrimethoxysilane,nonafluorohexyltriethoxysilane, nonafluorohexyltrimethoxysilane,pentafluorophenylpropyltrimethoxysilane,pentafluorophenyltriethoxysilane, bis(pentafluorophenyl)dimethoxysilane,(tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane,(tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane,p-trifluoromethyltetrafluorophenyltriethoxysilane,(3,3,3-trifluoropropyl)methyldimethoxysilane,(3,3,3-trifluoropropyl)trimethoxysilane, or combination thereof.

In one embodiment, two nanosurface modifiers are used, which may includefor example, polydimethylsiloxane diol andpoly[methyl(3,3,3-trifluoropropyl)siloxane] diol.

In one embodiment, the composition is optically transparent.

In one embodiment, (A) is present in the hybrid composition in an amountof about 50-95 wt % based on the weight of the composition. This rangeincludes all values and subranges therebetween, including 50, 51, 52,53, 54, 55, 56, 57, 58, 59, 60, 62, 64, 66, 68, 70, 75, 80, 85, 90, and95 wt %, based on the weight of the hybrid.

In one embodiment, (B) is present in the hybrid in an amount of about3-30 wt % based on the weight of the hybrid composition. This rangeincludes all values and subranges therebetween, including 3, 4, 5, 6, 7,8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, and 30 wt % based on theweight of the hybrid composition.

In one embodiment, (C) is present in the hybrid in an amount of about0.004-20 wt % based on the weight of the composition. This rangeincludes all values and subranges therebetween, including 0.004, 0.005,0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07,0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 12, 14, 16, 18, 20 wt %, based on the weight of thehybrid.

In one embodiment, (D) is present in an amount of about 0.004-20 wt %based on the weight of the composition. This range includes all valuesand subranges therebetween, including 0.004, 0.005, 0.006, 0.007, 0.008,0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2,0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12,14, 16, 18, 20 wt %, based on the weight of the hybrid.

In one embodiment, the reaction product comprises one or more compoundshaving the following formula (II):

-   -   wherein each Z is independently Si or H; and    -   wherein each R″_(D) is independently —CH₃, —CH₂CH₃, —CH₂CH₂CH₃,        —CH₂CH₂CH₂CH₃, or —OZ. In this embodiment, the Si may be a        siliceous silicon, or siloxane silicon. In one embodiment, the        Si is a siliceous silicon.

In one embodiment, the hybrid composition includes an SiO_(x) siliceousphase wherein x is 1.5-2. This range includes all values and subrangestherebetween, including 1.5, 1.6, 1.7, 1.8, 1.9, <2.0, and 2.

The hybrid coating may be applied to a surface.

In one embodiment, the coating has a peak ice removal force of 1-300kPa. This range includes all values and subranges therebetween,including 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,19, 20, 25, 30, 35, 40, 45, 50, 75, 80, 100, 200, 300 kPa.

One embodiment provides a coating composition, comprising:

-   -   (A) one or more compounds having formula (I);    -   (B) one or more alkoxysilane, alkoxysiloxane, or combination        thereof as mesosurface builder;    -   (C) optionally, one or more polydialkylsiloxane diol as first        nanosurface modifier,    -   (D) optionally, one or more fluorinated alkoxysilane as second        nanosurface modifier,    -   (E) optionally, one or more of a catalyst, water, or combination        thereof; and    -   (F) one or more solvent.

In one embodiment, the solvent (F) is tetrahydrofuran (THF),2-methyltetrahydrofuran (MeTHF), ethanol, 2-propanol, n-propanol,2-butanol, t-butanol, n-butanol, butyl acetate, acetone, ethyl acetate,or combination thereof.

One embodiment provides a method of making the composition of claim 15,comprising:

-   -   (1) reacting, in the presence of a first catalyst, one or more        soft block polymers R_(S) end-capped with —NH₂, —OH, or        combination thereof,    -   with one or more compounds having the formula:

-   -   to form one or more compounds having formula (I);    -   (2) contacting one or more compounds of claim 1 having        formula (I) with:    -   (B) one or more alkoxysilane, alkoxysiloxane, or combination        thereof as mesosurface builder;    -   (C) optionally, one or more polydialkylsiloxane diol as first        nanosurface modifier,    -   (D) optionally, one or more fluorinated alkoxysilane as second        nanosurface modifier,    -   (E) optionally, one or more of a second catalyst, water, or        combination thereof; and    -   (F) one or more solvent; and    -   (3) allowing at least a portion of the solvent to evaporate;    -   (4) to form the composition of claim 15.

In one embodiment, the composition comprises a mixture of:

-   -   the composition of claim 15; and    -   one or more thermoplastic polyurethane.

In one embodiment, the mixture is a blend, immiscible polymer blend,compatible polymer blend, miscible polymer blend, interpenetratingpolymer network, or combination thereof.

The thermoplastic polyurethane is not particularly limited, and may be alinear polymer, homopolymer, copolymer, thermoplastic elastomer, orcombination thereof.

In one embodiment, the thermoplastic polyurethane is a copolymercomprising one or more polyurethane and/or polyurethane urea segmentsand one or more polyether segment, polydiene segment, polyolefinsegment, polysiloxane segment, polyester segment, or combinationthereof.

In one embodiment, the thermoplastic polyurethane has a molecularweight, M_(w), of greater than 50,000 Da. This range includes all valuesand subranges therebetween, including 50,000, 55,000, 60,000, 65,000,70,000, 80,000, 85,000, 90,000, 100,000, 200,000, 300,000 Da, and higheras desired.

In one embodiment, the mixture comprises 20-80 wt % of the hybridcomposition and 80-20 wt % of the thermoplastic polyurethane. Theserespective ranges include all values and subranges therebetween,including 20, 22, 24, 26, 27, 29, 30, 33, 35, 37, 39, 40, 42, 43, 44,45, 47, 49, 50, 55, 60, 65, 70, 75, and 80 wt % as appropriate.

The hybrid/polyurethane composition may be suitably applied to asurface, to provide a surface having a peak ice removal force of 1-300kPa. This range includes all values and subranges therebetween,including 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,19, 20, 25, 30, 35, 40, 45, 50, 75, 80, 100, 200, 300 kPa. In oneembodiment, the peak removal force is less than 100, 75, 50, 40, 30, 20,10, and 5 kPa.

In one embodiment, a method of making the composition includes:

-   -   (1) reacting, in the presence of a first catalyst, one or more        soft block polymers R_(S) end-capped with —NH₂, —OH, or        combination thereof,    -   with one or more compounds having the formula:

-   -   to form one or more compounds of claim 1 having formula (I);    -   (2) contacting one or more compounds of claim 1 having        formula (I) with:    -   (B) one or more alkoxysilane, alkoxysiloxane, or combination        thereof as mesosurface builder;    -   (C) optionally, one or more polydialkylsiloxane diol as first        nanosurface modifier,    -   (D) optionally, one or more fluorinated alkoxysilane as second        nanosurface modifier,    -   (E) optionally, one or more of a second catalyst, water, or        combination thereof;    -   (F) one or more solvent; and    -   (G) one or more thermoplastic polyurethane; and    -   (3) allowing at least a portion of the solvent to evaporate;    -   (4) to form the composition.

In one embodiment, a coating composition, comprising:

-   -   the hybrid composition;    -   one or more thermoplastic polyurethane; and    -   one or more solvent.

In one embodiment, the coating composition includes:

-   -   (A) one or more compounds having formula (I);    -   (B) one or more alkoxysilane, alkoxysiloxane, or combination        thereof as mesosurface builder;    -   (C) optionally, one or more polydialkylsiloxane diol as first        nanosurface modifier,    -   (D) optionally, one or more fluorinated alkoxysilane as second        nanosurface modifier,    -   (E) optionally, one or more of a catalyst, water, or combination        thereof;    -   (F) one or more solvent; and    -   (G) one or more thermoplastic polyurethane.

In one embodiment, a method for coating, comprising:

-   -   contacting a surface with any of the coating compositions        described herein.

One embodiment provides monolithic, self-stratifying polymer coating,comprising:

-   -   inner and outermost surfaces on opposite sides of the coating,        the inner surface being in contact with and adhered to an        article;    -   a surface region, extending from the outermost surface to a        depth of about 1-5 nm from the outermost surface, which range        includes 1, 2, 3, 4, and 5 nm;    -   a middle region, extending between the surface region and the        inner surface, and having a thickness of about 1,000 nm-1,000        μm, which range includes 1000 nm, 2000 nm, 3000 nm, 4000, 5000        nm and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 200, 500, and 1000 μm; and    -   a bulk region, extending between the middle region and the inner        surface, and having a thickness of about 25 μm or more, which        range includes 25, 26, 27, 28, 29, 30, 100, 200, and 1000 μm.    -   wherein the surface region comprises one or more compounds        having formula (II):

-   -   wherein R_(S) is a soft block polymer;    -   wherein each T is independently a urethane or urea linkage;

wherein each p is independently 1, 2, or 3.

-   -   wherein each Z is independently Si or H; and    -   wherein each R″_(D) is independently —CH₃, —CH₂CH₃, —CH₂CH₂CH₃,        —CH₂CH₂CH₂CH₃, or —OZ;    -   in a greater concentration relative to the middle and bulk        regions;    -   wherein the middle region comprises —SiO_(1.5) in a greater        concentration relative to the surface and bulk regions;    -   and wherein the bulk region comprises a thermoplastic        polyurethane in a greater concentration relative to the surface        and middle regions.

The following table shows some nonlimiting examples of diols from whichthe soft block polymer R_(S) is derived. In one embodiment, diamine maybe used in place of the diol. Combinations of one or more diols,diamines, are possible.

Designation Full description Structure Polyether- based PTMOPoly(tetramethylene oxide)

PEO Poly(ethylene oxide)

PPO Poly(propylene oxide)

POM Poly(oxymethylene)

Polydiene- based PBD Polybutadiene diol

PIP Polyisoprene diol

Polyolefin- based PIB Polyisobutylene diol

Polysiloxane- based PDMS Polydimethylsiloxane

Polyester- based PCL Polycaprolactone

Polycaprolactone

Hydroxy terminated polyisobutylene

Pentamethylene/ Hexamethylene carbonate diol

Nonlimiting examples of the diamines may include the JEFFAMINE™diamines, D, ED, and EDR series available from Huntsman.

The following table shows some nonlimiting examples of the alkoxysilaneand alkoxysiloxane mesosurface builder useful for component (B).Combinations are possible.

PDEOS Poly(diethoxysiloxane)

PDMOS Poly(dimethoxysiloxane)

BTESE 1,2-bis(triethoxysilyl)ethane

1,4-bis(triethoxysilyl)benzene

1,2-bis(triethoxysilyl)ethylene

Bis(triethoxysilyl)methane

1,8-bis(triethoxysilyl)octane

1,10-bis(trimethoxysilyl)decane

1,6-bis(trimethoxysilyl)-2,5- dimethylhexane

1,2-bis(trimethoxysilyl)ethane

Bis(trimethoxysilylethyl)benzene

1,6-bis(trimethoxysilyl)hexane

1,4- bis(trimethoxysilylmethyl)benzene

1,8-bis(trimethoxysilyl)octane

Nonlimiting examples of the polydiethoxysiloxanes may include thePSI-021, PSI-023, and PSI-026 available from Gelest, Inc.

The following table shows some nonlimiting examples of the first andsecond nanosurface modifiers. Combinations are possible.

poly(dialkylsiloxane)diol

Poly[methyl(3,3,3- trifluoropropyl)siloxane]diol

Pentafluorophenyltrimethoxysilane

3- (heptafluoroisopropoxy) propyltrimethoxysilane

Nonafluorohexyltriethoxysilane

Nonafluorohexyltrimethoxysilane

Pentafluorophenylpropyltrimethoxysilane

Pentafluorophenyltriethoxysilane

Bis(pentafluorophenyl)dimethoxysilane

(Tridecafluoro-1,1,2,2- tetrahydrooctyl)triethoxysilane

(Tridecafluoro-1,1,2,2- tetrahydrooctyl)trimethoxysilane

p-trifluoromethyltetrafluorophenyltriethoxysilane

(3,3,3- trifluoropropyl)methyldimethoxysilane

(3,3,3- trifluoropropyl)trimethoxysilane

In the compounds in the tables above, the “n” value is not particularlylimited, and may independently and suitably range from 1-10,000. Thisrange includes all values and subranges therebetween, including 1, 2, 3,4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 500,700, 900, 1000, 2000, 2500, 5000, 7500, and 10000 and any combinationthereof.

In the compounds in the tables above, the “m” value is not particularlylimited, and may independently and suitably range from 1-10,000. Thisrange includes all values and subranges therebetween, including 1, 2, 3,4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 500,700, 900, 1000, 2000, 2500, 5000, 7500, and 10000 and any combinationthereof.

Catalyst

One embodiment provides an article selected from the group consisting ofa mat, tile, polyurethane, vinyl refrigeration hanging strip, airfoil,wing, propeller, hull, superstructure, railing, intake, hatch, keel,rudder, deck, antenna, medical device, kitchen device, counter, pipe,wind turbine, aircraft, ship, rotor blade, transmission tower,transmission line, cable, cooling coil, refrigerator, freezer, orcombination thereof, comprising any of the coatings or compositions on asurface thereon.

One embodiment provides a method, comprising applying any of thecompositions described herein to a surface, and allowing the compositionto cure, to produce a coated surface.

One embodiment provides a coated surface, comprising the cured productof any of compositions described herein in contact with a surface.

One embodiment provides a composition for coating, comprising any of thecompositions described herein and a solvent.

EXAMPLES Examples

The following examples are provided for illustration only and are notlimiting unless otherwise specified.

ER-Coat-1 and ER-Coat-2 Hybrid Coatings

Experimental Section

Materials.

Poly(tetramethylene) oxide 2000 g/mol (PTMO-2K) and dibutyltin dilaurate(T-12) were purchased from Aldrich. Isocyanatopropyltriethoxysilane(ICP-Si(OEt)₃), hydroxyl terminated poly (polydimethylsilane) cst(Silanol), and bis(triethoxysilyl)-ethane (BTESE) were purchased fromGelest, Inc. Tetrahydrofuran (THF) was purchased from Acros. Estane ALRE72A was purchased from Lubrizol. Isopropanol (IPA) was purchased fromFisher Scientific.

Preparative Procedures.

TPU Purification.

Example 1: Polyurethane Purification

In a 60 mL vial, 30 grams of methanol and 6 grams of THF were mixed.Into the vial, 3 grams of polyurethane pellets (Lubrizol EstaneALR-E72A) was added. The mixture was then heated to 60° C. PU pelletsswell to at least double their original size within one hour, whichfurther coalesced into one piece overnight.

Every 24 hours, a sample was taken and dried under vacuum to removesolvents. A few dried pellets were soaked in clean water that wasconfirmed by pre-interrogation water check with flamed glass slide anddynamic contact angle (DCA, Wilhelmy plate, degrees). After at least 5minutes of soaking the purified polyurethane pellets, the water waschecked with DCA using a flamed glass slide to determine whethercontamination is present (i.e., small molecule or surface activemolecules leaching out of the purified polyurethane). After at least 5minutes of soaking, a water check with DCA and flamed glass slide isdone to check whether contamination is detected. Samples were checked at24, 48, 72, and 96 hour. The results (not shown) indicate that for PUpellets soaked in methanol/THF mixture for 96 hours, water contaminationis negligible after 96 hours.

Example 2: Polyurethane Purification

In a 200 mL vial, 100 grams of ethanol and 20 grams of THF were mixed.Into the vial, 10 grams of polyurethane pellets (Lubrizol EstaneALR-E72A) was added. The mixture was then heated to 30° C. PU pelletsswell to at least double of its original size within 24 hours. Thepellets were soaked for 2 weeks and no significant coalescence wasobserved. Ten pellets were taken out and dried under vacuum to removesolvents. Five dried pellets were soaked in clean water that wasconfirmed by pre-interrogation water check with flamed glass slide.After at least 5 minutes of soaking, a water check with flamed glassslide showed no water contamination.

Example 3: Polyurethane Purification

In a 250 mL vial, mix 150 grams of IPA and 30 grams of THF. Into thevial, add 15 grams of polyurethane pellets (Lubrizol Estane ALR-E72A).The mixture was then heated to 40° C. PU pellets swell to at leastdouble of its original size within 24 hours. The pellets were soaked for1 week. Pellets are then filtered out and dried at 60° C. for overnightbefore vacuum dry at the same temperature for 24 hours. Samples areanalyzed by using GPC to confirm molecular weight.

TPU Molecular Weight.

A commercial thermoplastic polyurethane (TPU), Lubrizol Estane ALR-E72Awas used in place of HMDI/BD-30-(PTMO). While the structure of thispolymer is a trade secret, a survey of several candidates showed thatthis TPU has a similar FTIR spectrum, solubility and mechanicalproperties as the in-house base polyurethane. A purification process wasdeveloped for this commercial resin to remove processing agents andadditives that may affect the surface properties of the finishedcoatings. It was accidentally found that this purification processimproved ice release performance. GPC results (FIG. 1) showed a highermolecular weight for purified ALR-E72A and reduced molecular weightdistribution. Our working hypothesis is that the high molecular weightof this TPU resin was essential for driving sufficient phase separationwith the formation of functional mesosurface. The lower molecular weightfraction in the as received resin as well as the unknown processingadditives may be the cause for poor ice release performance. Even withhigh molecular weight and stratification promotion, excellentmiscibility of purified ALR-E72A with the PTMO hybrid solvent systemsmade for easy processing. Final coatings had good transparency. Opticaltransparency is essential for top coating for applications such as overdecals or over product identification information.

PTMO triethylsilane capping.

PTMO diol is first end-caped with ICP-Si(OEt)₃ at a mole ratio of 1:2with T-12 catalyst at elevated temperature (Scheme 1).

Example 1

6.4 g of PTMO-2K were dissolved with 12.0 grams of THF in a 20 mL screwcap vial. After complete dissolution of PTMO-2K, 1.6 g of (ICP-Si(OEt)₃)and 5 drops of T-12 (10 wt % solution) were added to the vial and mixeduntil homogeneous. The reaction mixture was placed in an oven at 60° C.for 4 hours. Reaction completion was determined by the disappearance ofthe isocyanate IR absorption peak at 2200 cm⁻¹. Final solutionconcentration was 40 wt %.

PTMO Hybrid Coatings (ER-Coat 1).

PTMO Hybrid coatings (ER-coat-1) were prepared base on desired hybridcontent by mixing end-caped PTMO (2), purified TPU and BTESE (Scheme 2).

Example 2

The hybrid coating consisting of 40 wt % triethylsilane capped PTMOhybrid and will be described. 9 g of THF were added to a screw cap vialfollowed by 0.6 g of Estane ALR E72A. The mixture was stirred to obtainhomogeneity. After stirring, 1 g of 40 wt % triethylsilane capped PTMOand 0.06 g of BTESE were added and mixed until homogeneous. The solutionis then drip coated onto glass microscope slides and left to cure atroom temperature for 24 hrs.

Example 3

2.215 gram of PTMO is mixed up with 0.572 gram of ICP-Si(OEt)₃ and 11gram THF and 2 drops of 10 wt % T-12 solution in a 20 ml glass vial. Thevial is agitated well to ensure dissolution of PTMO in THF, sealed andheated up to 60° C. for 4 hours. While the end-capping reaction takingplace, 2.810 gram of purified TPU was dissolved in 25 gram of THF. AfterTPU solution and end-caped PTMO are ready, they are mixed together with0.281 gram of BTESE. The mixture was stirred for 10 minutes beforecoatings were made on glass slides, primed aluminum substrates usingdrip-coat method.

PDMS Modified Hybrid Coatings (ER-Coat 2).

PDMS modified hybrid coatings (ER-coat-2) are prepared in a similarmanner as that of ER-coat-1. Since coatings with various hybrid and PDMSmodifier content have been prepared, the procedure for preparing a 40 wt% hybrid coating with 1 wt % PDMS will be given.

Example 4. 0.6 g of Estane ALR E72A was dissolved in a screw cap vialwith 8.3 g of THF until homogeneous. After mixing, 0.978 g of 40 wt %triethylsilane capped PTMO solution, 0.04 g of BTESE and 0.08 g of 5 wt% PDMS solution were added to the vial and mixed until homogenous. Thesolution is then drip coated onto glass microscope slides and left tocure at room temperature for 24 hrs.

Example 5

20.015 gram of PTMO is mixed up with 5.102 gram of ICP-Si(OEt)₃ and75.50 gram THF and 10 drops of 10 wt % T-12 solution in a 120 ml plasticbottle. The vial is agitated well to ensure dissolution of PTMO in THF,sealed and heated up to 60° C. for 4 hours. After reaction finished, thesealed bottle was placed in refrigerator prior to use. The solid contentof this solution is 25 wt %.

250 gram stock solution of 6 wt % TPU in THF was prepared with 15 gramTPU and 235 gram THF.

In a small glass vial, 0.673 grams of the previous prepared end-capedPTMO solution at 25 wt % solid content (net 0.0.168 gram end-caped PTMO)was mixed up with 4.180 gram TPU solution (0.251 gram TPU solid), 0.0022gram BTESE, and 0.0041 gram hydroxyl terminated PDMS. A coating of 50micron was made with this solution by drip coat 1 gram solution onto a1″×3″ glass slide.

Final Hybrid Percentage Calculation.

Hybrid percentage after curing was calculated to determine whether if itwas consistent with the feed of triethylsilane capped PTMO and BTESE. Asseen in Table 1, it has been confirmed that the final hybridconcentration is approximately 38%. This is within experimental error ofthe initial feed concentration of 40 wt % (Table 1).

TABLE 1 Final Hybrid Percentage Reactant Feed Reactant Feed Molecular orProduct (g) or Product (mol) weight, Da PTMO mod. 0.396 1.59E−04 2494.72PDMS 0.004 1.45E−06 2750 BTESE 0.04 1.13E−04 354.59 TPU 0.6 Evolved0.075 1.63E−03 Ethanol Net water 0.015 8.15E−04 reacted Hybrid solid0.380 TPU wt % 61.24

Mechanical Testing.

The mechanical strength of the new hybrid coatings was evaluated bytensile testing. Rectangular samples were cut from coated slides andmeasured for thickness, width, and gauge in millimeter. Samples werethen clamped into the holder of a TA Instruments RSA-III. The sampleelongation rate was 0.05 mm/s with a data acquisition rate of 1 Hz (24°C.). Tesile testing determined the strain at break for PTMO hybridsamples to be 600% and a ultimate strength to be 15 MPa.

Ice Release.

Ice release test were performed using the RSA-III with a modified forceprobe. Ice cylinders were prepared by freezing water on the surface ofthe hybrid coating via the use of molds 8-10 mm in diameter. Afterfreezing, samples were then placed in a fabricated holder in the RSA-IIIand the temperature of the sample chamber is allowed to equilibrate at−10° C. The probe speed (shear rate) was set to 3 mm/min (50 μm/s). Peakremoval stress (P_(s)) was determined along with removal energy (RE),which is the area under the curve, FIG. 2. The PTMO hybrid coatingcomposition that has thus far exhibited the best ice release propertiesis the 40 wt % PTMO hybrid with an average P_(s) of ˜180 kPa and a RE of0.01 kJ/m². The best performing PDMS modified hybrid coating has thusfar been the 40 wt % PTMO h]ybrid with 1 wt % PDMS (ER-Coat-2, shown inFIG. 3). Average P_(s) and RE where ˜80 kPa and ˜0.0086 kJ/m².

Comparison to Commercial Coatings.

FIG. 4 shows commercially available coatings for which ice releaseclaims have been identified. The bar graph shows peak removal force inshear, P_(S). The lower the peak removal force, the easier it is toremove ice. As seen in the figure, ER-Coat-2 has 40% easier ice removalcompared to Wearlon Super F-1. In addition, ER-Coat-2 is tough comparedto silicone competitors (e.g., Nusil, IceSlick, Wearlon, and CG²Nano-Coatings).

TABLE 2 Commercial coatings Wearlon Super F-1 Silicone-epoxy StaCleanFluoro-urethane/Silicone Nusil Silicone CG² NanoCoatings Siliconenanocomposites IceSlick Silicone 21^(st) Century Coatings Fluorinatedpolyurethane WC-1(ICE)

B. Specific Background.

A fundamental study of adhesion of epoxied aluminum cylinders (ECs) to anovel fluorous hybrid elastomer led to the discovery that adhesion inshear depends on three parameters: (1) work of adhesion, i.e. surfaceenergy (nanosurface), (2) near surface modulus (mesosurface), and (3)coating geometry, i.e. thickness (bulk). This three tier concept isillustrated in FIG. 5 and described in the paper “RigidAdherent-Resistant Elastomers (RARE): Nano-, Meso-, and MicroscaleTuning of Hybrid Fluorous Polyoxetane-Polyurethane Blend Coatings”. Itis important to note that the newly proposed mesosurface (˜1000 nm)contribution to diminishing adhesion in shear is not well understood. Itappears that a low modulus for the soft, near surface hybrid domaindecreases adhesion.

This fundamental study at Virginia Commonwealth University (VCU) onepoxied aluminum cylinders led to a study of ice adhesion, i.e., ice asa “rigid adherent”. Coatings were made on glass microscope slides and asample holder was devised for ice cylinders frozen onto these coatings.Preliminary studies at −10° C. using the same fluorous hybrid elastomersnoted above led to the exciting discovery that ice-adhesion strength isdependent on the same three coating parameters illustrated in FIG. 5.Furthermore, ice adhesion was found to be very low for optimum fluoroushybrid elastomer compositions (around 50 wt % urethane), which isexactly the compositional range that minimizes epoxied aluminum cylinderadhesion. A key advantage of these hybrid coatings is their mechanicalstrength and easy processing.

The underpinning for the three-parameter dependence of ice adhesion (andEC adhesion) is Kendal adhesion theory for force required to remove arigid object from an elastomer (FIG. 5, Eq 1). Kendall developed thistheory for adhesion of a rigid object bonded to an elastomeric thinfilm. While acknowledging that the “fit” of this theory to micron scalecoating is only approximate, the guidance of theory has provedimportant. In addition, we have learned invaluable “practical lessons”that have resulted from systematic studies of composition and processingparameters.

Moving on from expensive fluorous polymeric materials, this SBIR Phase Iproject was proposed to partially or completely replace fluorouscoatings with relatively inexpensive, commercially available engineeringmaterials. The objective was to use the new model described in FIG. 5 toengineer economical coatings having excellent ice-release properties.Scheme 4 illustrates our present “state-of-the-art” that will bedescribed further.

C. Details on Accomplishments.

(1) Ice Release Test Method.

Ice adhesion tests were conducted by using a commercial RSA-III DynamicMechanical Analyzer (DMA) by TA Instruments. The RSA-III has acontrolled temperature chamber that was fitted with a speciallyfabricated glass microscope slide holder as shown in FIG. 6. ² For iceadhesion tests, temperature control is achieved with an accuracy of±0.5° C. from −90 to −5° C. with the controller cooled by liquidnitrogen boil-off. The RSA-III has a 3.5 kg load cell having 0.2 mgresolution. The low stress limit of this load cell provides precisionand accuracy are achieved for measuring weakly bonded objects. Coatingswith high ice-adhesion strength cannot be tested but they are not ofinterest.

(2) Coating Component Characterization and Tests.

A recent breakthrough-coating designated

ER-coat-2 was developed guided by theory and our experience. Thestrategy for nanosurface, mesosurface and bulk engineering is shown inScheme 1. FIG. 7 shows a typical test result for the most recentlydeveloped hybrid ER-coat-2 coating. The ice cylinder contact area isconstant so that force is shown as stress (kPa). The maximum before icecylinder removal is the peak removal force in shear, designated P_(s).By using the RSA III test method, coating development was accelerateddue to fast testing turn-around time. Evaluation of peak removal forceP₅ for ice release via a laboratory based test has explored for manycoating compositions and processes.

PEG LLC also evaluated coatings with third party testing facilities atPenn State. The results obtained validated PEG LLC's ice adhesionmeasurements using the RSA III. The ER-coat-2 coating was independentlyprepared three times and tested several times to confirm ice-adhesionstrength less than 100 kPa (FIG. 8). Ice adhesion strength less than 100kPa or 0.10 MPa is considered the threshold for many practical de-icingapplications. The low P_(s) for ER-coat-2 is nearly as good as thefluorous hybrid coating that initially sparked our interest.

The mechanical strength of the new hybrid coatings was evaluated bytensile testing. A 700% of strain at break and a 10 MPa ultimatestrength were found. Based on mechanical and physical properties,promising erosion and wear resistance are anticipated; these featuresare important for many deicing applications that face challengingenvironmental conditions. A systematic study of erosion/wear resistanceis planned for Phase II research and development. A Phase II planaddresses the development of coatings with even lower ice adhesionstrength.

a. Nanosurface.

Initially, we used a commercially available fluorous polyoxetane (3F and5F) to decrease work of adhesion. 3F and 5F resulted in phase separationdescribed in Section 3. As an alternative, we turned to silicone (PDMS)surface modification. Thus far, the relationship of wt % PDMS andcoating thickness has been explored. These are inter-related asdescribed below. A PDMS diol with a molecular weight of 5 kDa was chosenfor nanosurface modification. As noted above, a 50 μm ER-coat-2 coating(1 wt % PDMS) had a peak removal force P_(s) less than 100 kPa, whichwas the lowest peak removal force of all coatings tested (FIGS. 6, 7,and 8).

In a study of the effect of surface modifier wt % on peak removal force,more surface modifier was found to give higher peak removal force. FIG.9 shows the dependence of P_(s) on PDMS content from 1 to 3 wt % for ahybrid system contains 60 wt % polyurethane (40 wt % hybrid) at threedifferent thicknesses. The complex interplay of thickness and modifieris evident. Without question, the best performer (noted above) wasER-coat-2, 50 μm and 1 wt % PDMS nanosurface modifier.

Perhaps higher surface modifier weight percent (2, 3) leads tonanosurface and mesosurface phase separation that sequesters the PDMSfunction. The “More is Less” phenomenon was reported by Zhang and Wynnefor a PDMS system with a perfluorinated surface modifier. ⁵ In thiscase, “More is Less” referred to a high contact angle that “crashed”above concentration modifier that caused near surface phase separation.

It is not clear why the ER-coat-2 composition with 1 wt % PDMS andthickness (50 μm) gives such a low ice removal force. Work will beproposed in Phase II to explore what factors contribute to this finding.Contributors may be PDMS molecular weight, BTSE wt % (which generatesthe mesosurface hybrid composition), and/or feed sequence for theprecursor coating solution. We recognize that Scheme 1 providesguidance, but specific experimental parameters that optimize ice releasemust be determined by systematic R&D including the engineering approachof “Design of Experiment”. In the meantime, the optimum composition,designated ER-coat-2 is being used for tests at Smithfield Foods inconnection with formation of a strategic partnership and productdevelopment that will be described in the Phase II commercializationplan.

b. Mesosurface.

Previously, we explored the compositional dependence of “U-3F-x” onepoxied aluminum cylinder adhesion. ¹ For minimizing adhesion, a “sweetspot” was found in the range 40-50 wt % linear polyurethane U-3F,alternatively expressed as 60-50 wt % hybrid component. Furthermore,ATR-IR spectroscopic evidence showed that the hybrid component was“mesosurface-concentrated” (FIG. 2) and contributed to easy release inshear.

Guided by the prior findings, a range of 40-60

wt % polyurethane was studied to establish the contribution ofhybrid/mesosurface (no PDMS modifier). FIG. 10 shows that the ER-coat-1system with 45-60 wt % polyurethane has much easier ice releaseperformance compared to the polyurethane (100% TPU) or the 100% hybrid.The working hypothesis to explain the remarkably low ice release of the50 wt % urethane ER-coat-1 system is the soft mesosurface illustrated inFIG. 2.

It should be noted that only cohesive failure was observed for icefrozen on 100% TPU. That is, the locus of fracture was within the icecylinder, not at the ice-polymer interface. Further tests andcompositional variations are currently being conducted and will beproposed for Phase II to explore whether even better performance can berealized.

c. Bulk Polyurethane.

In prior work, a high molecular weight (M_(w), 110 kDa) fluorouspolyurethane “U-3F” was employed. ¹ Our initial encouraging results forER-coat-1 were obtained with a purified commercial thermoplasticpolyurethane (TPU), Lubrizol Estane ALR-E72A that had a high molecularweight: M_(w)˜233 kDa. Later, another ER-coat-1 coating was made withlaboratory prepared polyurethane of a similar composition but M_(w) of˜20 kDa. To our dismay, the hybrid coating made with the 20 kDapolyurethane had a high peak removal force for ice release that waslittle better than the polyurethane itself (no hybrid component). Ourworking hypothesis to explain this result is that the high MWpolyurethane drives mesosurface/bulk phase separation essential for lowice release. As a result, we have used high MW polyurethanes for “bulk”composition. There are other important details with regard to the bulkpolyurethane noted in the section “Problems Encountered and Methods ofResolution”.

(3) Thickness Dependence of Ice Release.

Based on Kendall theory, peak removal force has an inverse linearrelationship with square root thickness, (1/t^(1/2)). To investigatethickness dependence, hybrid elastomer coatings having 50 wt %polyurethane (ER-coat-1) were prepared without PDMS nanosurfacemodifier. FIG. 11 shows the dependence of P_(s) on coating thickness.Over the thickness range of 5-15 μm, P_(s) decreases by a factor of ˜2.Because these coatings do not have a PDMS modified nanosurface, aminimum for P_(s) is ˜200 kPa at the higher coating thickness range(˜100 μm). Overall, there is very good agreement with Kendal theory.Perhaps the dependence of peak removal force on thickness asymptotes at˜50 to 150 μm. Studies will be proposed for Phase II to confirm thisfinding and to investigate the relationship of thickness to wt % PDMSmodifier.

(4) Ice Adhesion Test Check at an Aerospace Facility.

There is no standard method for testing ice adhesion. A goal of thePhase I effort was to compared the VCU laboratory test proceduredescribed above with results from a well-known aerospace facilitydedicated to ice release testing. To investigate this issue, Dr. Jose L.Palacios, Director of the Adverse Environment Rotor Test Stand (AERTS)facility in the Aerospace Engineering Department at Penn StateUniversity was contacted. Dr. Palacios introduced us to the AERTS testprocedure, which is explained briefly here. FIG. 12 shows the rotorbeam, with coated coupons mounted on the end of test beam leading edge.This test was designed to reproduce natural icing conditions such asthose on a helicopter rotor or airplane wing. The rotor for the PennState test has a diameter of 10 ft and tip speeds up to 470 ft/s.

When subjected to an icing environment, ice accretes on the testspecimen. This additional mass increases the centrifugal force of thecoupon assembly on the beam, causing it to deflect and to increase thestrain read by the strain gauge mounted at the base under the coating.When ice reaches a critical mass, it releases from the fixture,instantly reducing the strain in the beam. The critical ice mass relatesto the ice adhesion strength. The change in strain can be related to theice mass on the beam prior to release. ⁶⁻⁸

A set of hybrid coatings without PDMS surface modifier (ER-coat-1) wasevaluated using the AERTS facility at Penn State. Two sample thicknesseswere chosen: 100 and 300 μm (FIG. 13). The experiment was carried out attwo temperatures, −8 and −12° C. The selection of these two temperaturesresulted from the cooling capacity of the system and on the airtemperature at the test time. FIG. 13 shows the testing results for thetwo ER-coat-1 systems. Ice adhesion strength is below 100 kPa at −8° C.and ˜150 kPa at −12° C.

VCU tests for ER-coat-1 coatings with ˜150 μm thickness gave P_(s)˜180kPa (FIG. 11). Considering the differences in ice formation andhandling, the data acquired at AERTS are in fair agreement with PEGLLC's tests using the RSA III. The AERTS data shows lower ice adhesionstrength at −8° C. than at −12° C. The Penn State test involves anexothermic phase transition (water droplets →ice) right on the coatingsurface. Thus the sprayed water droplets increase the temperature duringa test run. Therefore, the actual temperature on the ice/coatinginterface may not be quite as low as the designed temperature. This mayexplain why the Penn State −12° C. results agree more closely with VCUdata at −10° C. This result provides confidence and validation to ourlaboratory-devised RSA III testing method.

In April 2013 ER-coat-1 was chosen for Penn State testing beforeER-coat-2 (PDMS modified) coatings were developed in May. Also, thistest was carried out before details of thickness dependence were known(FIG. 11). In Phase II we will propose additional tests at Penn State onER-coat-2 systems. Such tests will move PEG LLC forward in establishingcredibility for wind tunnel tests at Boeing and other aerospacefacilities.

(5) Temperature Dependence of Ice Adhesion.

Little is known about the dependence of ice release on temperature forpolymeric coatings. However, this knowledge is critical forrefrigeration applications. For example, in “flash freeze” areas of foodrefrigeration plants, freshly prepared vegetables and meats drip wateron the floor prior to freezing and creating a hazardous ice plaque.

The temperature dependence of ice adhesion on polymer coatings dependson the changing physical properties of ice and phase transitionsassociated with coatings. Saeki ⁹ and Palacios ⁸ reported almost linearincrease in ice adhesion strength with decreasing temperature on metalsubstrates, but virtually nothing is known for polymer coatings. Forelastomeric polymer materials, moduli change with decreasingtemperature, especially when approaching the glass transitiontemperature. As indicated by the Kendal Equation (Eq 1.), an increase insubstrate modulus results in higher adhesion strength for a rigidadherent.

In this project, preliminary results were obtained at two differenttemperatures, −10

TABLE 2 Solvent table for thermoplastic polyurethanes and coatingsystems. Solvent system Comments THF Used ER-coat-0, ER-coat-1,ER-coat-2, excellent solvent. MeTHF Tested successfully for ER-coat-0,ER-coat-1, ER-coat-2, excellent solvent. Ethanol Cannot be used alone todissolve ER-coat-0, ER- coat-1, ER-coat-2. A mixture containing up to 50wt % ethanol (with THF) was used and no difference was found in coatingsfrom those made with THF. One of the best ER-coat-2 coatings was madewith this solvent system. Mixtures with MeTHF behaved the same as thosewith THF. 2-Propanol Pure IPA behaved similar to ethanol. Mixtures of(IPA) IPA (up to 30 wt %) and THF can be used for dissolving ER-coat-0,ER-coat-1, ER-coat-2. n-Propanol Pure n-propanol is a better solventthan IPA and ethanol for ER-coat-0, but not as good as that of THF. Nofurther tests at this time. 2-Butanol Cannot be used along as a solventfor ER-coat- 0, mixtures of 2-butanol (30 wt %) and THF were goodsolvents. tert-Butanol Similar to 2-butanol. n-Butanol Similar to2-butanol. Butyl acetate Similar to n-propanol Acetone Similar butbetter than IPA Ethyl acetate Poor solvent for ER-coat-0. Mixturescontaining 50% THF tested well.and −20° C. FIG. 14 shows the dependence of ice adhesion strength forER-coat-2 systems with 1-3 wt % PDMS. There is a systematic increase inice adhesion at −20° C. compared to −10° C. for 1 and 2 wt % nanosurfacemodification. Interestingly, for the thicker (100 and 150 μm) coatingsat 3 wt % PDMS, P_(s) is virtually the same at both temperatures. TheT_(g) for PTMO (2 kDa) is −65° C. while that for PDMS is −110° C. Thus,the effect of T_(g) in rigidifying the mesosurface at the lowertemperature may have been modulated by the higher (3 wt %) PDMS content.In Phase II we will propose a systematic study of the temperaturedependence of ice adhesion. This will be an important effort asapplications such as “flash freeze” chambers noted above operate at −20°F. or −29° C. An essential part of our development plan for Phase IIwill be to retain <100 kPa for P_(s) at temperatures as low as −30° C.

Work Task 2: Optimization of Ice-Release Performance

TABLE 2 DOE compositional independent variables. Independent Range ofvariations for independent variables variable Molecular Concentration/categories Specific material variables weight composition Nano- PDMSDifunctional 1,000-26,000 Da 0.5 wt %- Surface Mono-functional,di-functional 10 wt % Modifier Mixed Select from above (e.g., M_(w) 0.5wt %- Surface difunctional/monofunctional PDMS) distribution 10 wt %Modifiers Mesosurface Poly(tetramethylene oxide), PTMO <1,000-5,000 Da40-60 wt % Polypropylene oxide, PPO of coating Polyisobutylene, PIBMesosurface BTESE, bis(triethoxysilyl)ethane 1 w %-30 wt % Builder ES40or ES50 (poly(diethoxysiloxane) of mesosurface Bulk Thermoplasticpolyurethane (TPU), >100 kDa 60-40 wt % PDMS-PU, PDMS-PUU of coating

Although guided by theory (FIG. 2, Scheme 1), considering many possiblevariations in nanosurface modifiers, mesosurface “builders”, and bulklinear polyurethanes (and thickness) we were fortunate to discoverER-coat-2 (1 wt % PDMS) at 50 μm. To make rapid progress in Phase II,DOE will be performed to improve further ice-release performance.

Independent variables affecting (or that are likely to affect) peakremoval force include those determining composition (Table 2) and thoseinvolving processing (Table 3).

TABLE 3 DOE processing independent variables Independent Range ofvariations for variable categories independent variables Solvent Singlecomponent solvents system Concentration Solvent mixtures (Table 5)Solvent ratios Solute concentration Drying Solvent evaporation rate byconditions controlling air flow and vapor pressure Temperature CuringTemperature from RT to 100° C. conditions Time (30 min to 24 hr) CoatingDrip or Dip coating preparation Spraying method Melt pressing/laminationOvercoatingAs suggested in FIG. 2 and Scheme 1, compositional variables that willbe evaluated in Phase II include (1) the type, content and molecularweight of nanosurface modifier, (2) the type and content of mesosurfaceand mesosurface builder, and (3) the type, content and molecular weightof bulk polymer.

Multiple DOEs will be devised from coarse to fine variations incomposition and processing based on a manageable experimental size.These variables will affect the surface chemical composition, recedingcontact angles, mechanical properties, and phase separation of thecoating components.

Processing variables that are likely to affect the key dependentvariable (P_(S)) include (1) selection of solvent system (mixture andcompositions of solvent mixtures), (2) drying conditions (controlledsolvent evaporation rate), (3) curing conditions (temperature and time),and (4) coating preparation method (spraying, brush ormelt-pressing/laminating, overcoating multilayers). These variables arecritical to coating layer stratification, mesosurface formation,concentration of surface function, and surface topology as well asassessing the optimum approach for scaleup and larger scalemanufacturing.

C. Improving Low Temperature Performance.

For many applications such as commercial refrigeration discussed above,performance at temperatures lower than those typically reported for icerelease tests (−10° C.) are of critical importance. FIG. 7 shows P_(S)for ER-coat-2 with 1, 2, and 3 wt % PDMS modifier at different coatingthicknesses. P_(S) generally increases at −20° C. compared to −10° C.The least effect for the lower temperature is seen for the two thicker 3wt % PDMS modified coatings.

The general trend of higher peak removal force at lower temperatures isreadily understood with reference to the Kendall equation (Eq 1). Astemperature decreases coatings become more rigid as the glass transitiontemperature (T_(g)) is approached. As the coating becomes more rigid(higher modulus, E) the peak removal force increases (Eq 1).

Although the prediction from Kendall theory is clear and offers atheoretical basis for preliminary results in FIG. 7, published workprovides virtually no guidance as most testing is at −10° C. Thepioneering research of Jellinek 35 years ago addressed temperaturedependence, but results were not clearly related to polymer structureand composition.³ Considering the importance of easy ice release at lowtemperatures for refrigeration, aerospace, and energy sectors, thedetermination of P_(S) as a function of temperature is a priority forPhase II research and development.

An important factor in considering low temperature performance is notonly the nominal glass transition temperature, but the breadth of T_(g)and the modulus at use temperature. To illustrate, FIG. 8 shows aschematic generated from DMA data for PDMS and PTMO polyurethanesreported by Cooper.¹

The PDMS soft block is extremely well phase separated giving a sharpT_(g) near that for the soft block alone and a relatively flat plateaumodulus. The PTMO polyurethane has a broader and higher T_(g) resultingin a considerable change in modulus over the temperature range ofinterest (−10 to −30° C.). While the two red lines that define themodulus at −10 and −30° C. seem close together, the ordinate is a logscale. Like this example, the modulus doubles from −10 to −30° C. formany PTMO-based polyurethanes. This factor of two is importantconsidering the relationship of modulus to P_(S). While T_(g) isavailable from most resin suppliers and can be used for a roughscreening, data shown in FIG. 8 is not available. To rationally improveice release performance, DMA is seen as an essential characterizationmethod. In this proposal a DMA instrument is requested not only toperform P_(S) measurements, but also to analyze commercially availablematerials for correlation with P_(s) so as to rapidly move forward withbulk polyurethane candidates.

Work Task 3: Optimization of Low Temperature Performance

Increased modulus at lower temperatures is the principle changeaffecting ice adhesion (Equation 1), as to a first approximationthickness and work of adhesion remain constant. For polymer materials,modulus (stiffness) gradually increases as temperature decreases and theglass transition temperature is approached. At T_(g) the modulusincreases markedly. Therefore, this work task is designed to incorporatelowest possible T_(g) polyurethane into ER-coat coatings.

Poly(dimethylsiloxane) networks (silicones, PDMS) are well known for lowT_(g) (−110° C.) but PDMS elastomers are particularly poor candidatesfor i-Mats due to poor wear resistance and poor adhesion to substrates.We will seek methods that utilize PDMS networks while retaining goodmechanical properties. The first priority in this regard is acomprehensive assessment of the effect of PDMS molecular weight andweight percent on peak removal force for ER-coat-2 systems. So far, onlya limited compositional range and one molecular weight (5 kDa) has beeninvestigated (FIGS. 5 and 6). This work received first priority becauseof success so far with the hybrid model shown in FIG. 2 and remarkableresults for ER-coat-2 (1 wt % PDMS) shown in FIG. 4.

TABLE 4 Commercially available soft blocks, glass transitiontemperatures, and TPU commercial availability. T_(g,) ° C. TPUcommercial Soft Block (in polymer, if known) availability PTMO −60(DMA), −77 (DSC) Many suppliers and (2000) grades, e.g. LubrizolPellethane ® and Tecoflex ® TPU Proprietary −75 (DSC) Lubrizol EstaneALR- E72A (M_(w) ~233 kDa) PPO −35 to −50 Many suppliers and grades,e.g. Merquinsa Pearlcoat ® 165K

The mesosurface also requires materials with a low glass transitiontemperature. As illustrated in Scheme 1, mesosurface precursors are madefrom a difunctional polyether. Table 4 shows commercially availabledifunctional polyethers that can be used for polyurethane soft blocksand mesosurface precursors. It should be noted that T_(g) also dependson soft block molecular weight. Usually, higher molecular weight resultsin lower T_(g) (better phase separation) provided crystallization isabsent.

In Phase II, difunctional polyethers and combinations thereof (Table 4)and commercially available low T_(g) polyurethanes will be used toachieve low P_(S) at low temperatures. Again, the DOE method will beused to quickly find optimum combinations.

D. Environmentally Benign Processing.

Reducing or eliminating organic solvents from coating preparationprocesses are goals to reduce manufacturing cost and assure a saferworking environment. Tetrahydrofuran (THF) was used for coating systemsin Phase I. On a small scale, THF is acceptable, but volatility,peroxide formation, and EPA/OSHA regulations result in increasedmanufacturing costs during scale-up partly due to solvent recovery.

An important achievement in Phase I was finding a replacement for THF,namely 2-methyltetrahydrofuran (MeTHF), which does not form peroxides.Other solvents and solvent mixtures explored are listed in Table 2 ofthe Phase I final report. Optimizing and reducing solvent use will bethe subject of continuous study in Phase II so as to reduce cost andoptimize performance.

The i-Mat product does not involve solvent exposure for commercialfreezer applications in food processing. Also, i-Mats can be installedwithout disrupting normal operations. As noted above, Phase IIdevelopment will emphasize development of ER-coat films such asER-coat-2 (1% PDMS), 50 μm, that can be thermally bonded to substrates.This is an exciting option as:

(1) Solvent used for ER-coat film formation can be recycled as ispresently done during drying/cure by passing air through a cold trap

(2) The resulting ER-coat film that will be used for thermal bondingwill be formed on a reusable release surface their boiling points

(3) The released film depicted in FIG. 2 is well suited to thermalbonding as the bulk is a thermoplastic polyurethane, while the hybridfunctional nanosurface and mesosurface are crosslinked and thermallyinsensitive.

TABLE 5 Solvent candidates and their boiling points Solvent candidatesBoiling Point (° C.) THF 66 MeTHF 80 Ethanol 78 2-Propanol (IPA) 83n-Propanol 97 2-Butanol 100 tert-Butanol 82 n-Butanol 117 Butyl acetate126 Acetone 56 Ethyl acetate 77

Work Task 4: Development of Environmentally Benign Processing

Limited work on solvent mixtures was carried out in Phase I with an eyeto controlling the surface morphology (FIG. 2) and topology (roughness)by adjusting solvent evaporation rates. In Phase II, hazardous solventreduction will be based on (1) solvent system selection based on theprinciple of introducing less hazardous systems that facilitate thecoating preparation process and lower processing cost and (2) in-housemanufacturing of ER-coat films for thermal bonding, where solvents willbe recovered during cure and film formation.

Candidates to be explored in Phase II are in connection with DOE oncoating compositions and processing conditions. Table 5 lists organicsolvents explored in Phase I. Except for THF and MeTHF, these solventscannot be used alone because of poor polyurethane solubility. However,some solvent mixtures with THF and/or MeTHF were good for U-233 kDa andmay facilitate the nanosurface/mesosurface morphology favoring icerelease (FIG. 2, Scheme 1). Other polyurethanes to be studied under WorkTask 3 may have different solubility parameters and that requireselection of different solvent systems.

“Solventless” systems are widely employed in polyurethane coatings. Inaddition to physical crosslinking (H-bonding) such systems involvecovalent bond formation (chemical crosslinking) to enhance strength andtoughness. If stratification can be retained (FIG. 2) economicalsolventless coatings are attractive for applications such as in-servicecoating of wind turbine blades and electrical wires. Overcoating seemsto be the only practical process, whereby a first coat is a standardthermosetting polyurethane followed by a top coat (ER-coat). Goodbonding is required so overcoating will be done prior to completethermoset cure. Polyurethane and polyurea based systems will be firstchoices. Such coating systems are readily available. Table 6 listsselected candidates for this work task. Possible pitfalls for suchsystems are the presence of unknown additives and impurities in theseindustrial grade systems that could jeopardize the benefit ofnanosurface modification.

TABLE 6 Solventless system candidates Supplier Product # or Trade nameTwo-Component Systems Bayer Baytec ME-120, ME-230 Mearthane Durethane ™S DS-360A, 350A, 340A, 330A Polyol/Polyisocyanante Components InvistaTetrathane ® PTMO polyol BASF Lupranol ® and Pluracol ® polyetherpolyols Lupranate ® isocyanantes Bayer Desmodur ® isocyanates Arcol ®polyether polyol

ER-Coat Example

A hybrid stock solution of 5 grams containing 25% solid content (1.25gram) was first prepared. In a plastic bottle, 0.42 grams (1.68 mmole)poly(tetramethylene oxide) diol (250 grams/mole, PTMO), 0.83 grams (3.36mmoles) of 3-isocyanatopropyltriethoxysilane (ICPES), 0.01 gram ofdibutyltin dilaurate (DBTDL, or T-12) catalyst solution (10 wt % inTHF), and 3.75 gram THF was added. The HDPE plastic bottle was sealedafter as much air as possible was removed. The bottle was then placed ina 60° C. oven for four hours. The PTMO hybrid stock solution was thenremoved from the oven and used for next step or placed in therefrigerator.

Prior to creating the composition, other necessary stock solutions weremade. A 10 wt % poly(diethoxysiloxane) (PDEOS) (unit MW 134.20grams/mole) stock solution was prepared by adding 1.00 g of PDEOS to9.00 grams of THF. A 2 wt % stock solution of silanol-terminatedpolydimethylsiloxane (PDMS) was prepared by adding 2.01 g of PDMS (Mn4200 daltons) to 98.07 g of THF. The stock solution of thermoplasticpolyurethane (purified Lubrizol Estane® ALR E72A, TPU) in THF wasdetermined to be 16.99 wt %.

3.33 grams of 16.99% solid TPU stock solution (0.57 grams solid TPU) wasadded to 1.51 grams of 25% solid PTMO hybrid stock solution (0.38 gramssolid). 0.05 grams of ES40 was present in the 0.47 grams of the 10% ES40stock solution; this was also added to the solution of stock TPU andPTMO hybrid. PDMS was added so that it's weight was 1% of the combinedweight of the solid TPU and PTMO hybrid. This was calculated to be 0.01grams of solid PDMS. 0.01 grams of solid PDMS was added to the solutionby adding 0.47 grams of the 2% PDMS stock solution. To achieve asolution with 7.5 wt % solid, a percentage for coating a microscopeglass slide with about 1.25 grams of solution to achieve a coating ofapproximately 50 micons, 7.51 grams of extra THF was added to thesolution.

Four glass microscope slides (1″×3″) were labeled and coated each with1.25 grams of solution in a glove bag. The slides were partially coveredto slow the evaporation rate of the solvent thus creating a smoothersurface. The slides were left in a glove bag overnight. The nextmorning, the slides were moved from the glove bag to the 60° C. oven.The slides were removed from the oven after overnight drying and curing.Each glass slides were cut into three 1″×1″ squares so that a total 121″×1″ slides were available for ice release test and retest after oneweek. The coatings averaged a peak removal force of approximately 19.4kPa and a standard deviation of 8.4 kPa with total 24 measurements.

The entire contents of international applications PCT/US12/48425, filedJul. 26, 2012, and PCT/US13/57874, filed Sep. 3, 2013, and U.S.application Ser. No. 13/665,915, filed Oct. 31, 2012, are herebyincorporated by reference.

What is claimed is:
 1. A composition, comprising a reaction product of:(A) one or more compounds having the following formula (I); (B) one ormore alkoxysilane, alkoxysiloxane, or combination thereof as mesosurfacebuilder; (C) one or more polydialkylsiloxane diol as first nanosurfacemodifier; (D) optionally, one or more fluorinated alkoxysilane as secondnanosurface modifier; (E) optionally, one or more of a catalyst, water,or combination thereof; (F) optionally, one or more solvent; and (G)optionally, one or more thermoplastic polyurethane; wherein formula (I)is:

wherein R_(s) is a soft block polymer; wherein each T is independently aurethane or urea linkage;

wherein each R_(D) is independently —CH₃, —CH₂CH₃, —CH₂CH₂CH₃, or—CH₂CH₂CH₂CH₃; wherein each R′_(D) is independently —CH₃, —CH₂CH₃,—CH₂CH₂CH₃, —CH₂CH₂CH₂CH₃, or —OR_(D); wherein each p is independently1, 2, or 3; wherein the soft block polymer R_(s) is not a polyoxetane;and wherein the soft block polymer R_(s) is a polyether, polydiene,polyolefin, polysiloxane, polyester, or combination thereof; and wherein(C) is present in an amount of about 0.004-20 wt % based on the weightof the composition.
 2. The composition of claim 1, wherein the softblock polymer R_(s) is a linear homopolymer or copolymer.
 3. Thecomposition of claim 1, wherein each R′_(D) is independently —CH₃,—OCH₃, or —OCH₂CH₃.
 4. The composition of claim 1, comprising two ormore different compounds of formula (I), wherein a first soft blockpolymer R_(s) in one compound having formula (I) has a molecular weight,M_(w), of 200-1,000 Da, and a second soft block polymer R_(s) in adifferent compound having formula (I) has a molecular weight, M_(w), of1,500-3,000 Da.
 5. The composition of claim 1, wherein mesosurfacebuilder (B) is one or more of poly(diethoxysiloxane) (PDEOS),poly(dimethoxysiloxane) (PDMOS), 1,2-bis(triethoxysilyl)ethane (BTESE),1,4-bis(triethoxysilyl)benzene 1,2-bis(triethoxysilyl)ethylene,bis(triethoxysilyl)methane, 1,8-bis(triethoxysilyl)octane,1,10-bis(trimethoxysilyl)decane,1,6-bis(trimethoxysilyl)-2,5-dimethylhexane,1,2-bis(trimethoxysilyl)ethane, bis(trimethoxysilylethyl)benzene,1,6-bis(trimethoxysilyl)hexane, 1,4-bis(trimethoxysilylmethyl)benzene,1,8-bis(trimethoxysilyl)octane, or combination thereof.
 6. Thecomposition of claim 1, wherein the first nanosurface modifier (C) ispolydimethylsiloxane diol, polydiethylsiloxane diol, or combinationthereof.
 7. The composition of claim 1, wherein the second nanosurfacemodifier (D) is poly[methyl(3,3,3-trifluoropropyl)siloxane] diol,pentafluorophenyltrimethoxysilane,3-(heptafluoroisopropoxy)propyltrimethoxysilane,nonafluorohexyltriethoxysilane, nonafluorohexyltrimethoxysilane,pentafluorophenylpropyltrimethoxysilane,pentafluorophenyltriethoxysilane, bis(pentafluorophenyl)dimethoxysilane,(tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane,(tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane,p-trifluoromethyltetrafluorophenyltriethoxysilane,(3,3,3-trifluoropropyl)methyldimethoxysilane,(3,3,3-trifluoropropyl)trimethoxysilane, or combination thereof.
 8. Thecomposition of claim 1, which is optically transparent.
 9. Thecomposition of claim 1, wherein (D) is present in an amount of about0.004-20 wt % based on the weight of the composition.
 10. A surfacecoating, comprising the composition of claim
 1. 11. An article, having asurface in contact with the composition of claim
 1. 12. A composition,comprising a mixture of: the composition of claim 1; and one or morethermoplastic polyurethane.
 13. The composition of claim 12, wherein thethermoplastic polyurethane is a copolymer comprising one or morepolyurethane and/or polyurethane urea segments and one or more polyethersegment, polydiene segment, polyolefin segment, polysiloxane segment,polyester segment, or combination thereof.
 14. The composition of claim12, wherein the mixture comprises: 20-80 wt % of the composition ofclaims 1; and 80-20 wt % of the thermoplastic polyurethane.
 15. Thecomposition of claim 12, wherein the mixture is optically transparent.16. A surface coating, comprising the composition of claim
 12. 17. Anarticle, having a surface in contact with the composition of claim 12.18. The article of claim 11, which is a mat, tile, polyurethane, vinylstrip, or a combination thereof.